The present invention generally relates to the use of location finding equipment (LFE) or position determination equipment (PDE) in relation to a mobile communications system (e.g., a wireless network) and, more particularly, to managing the provisioning of location information on mobile communications units.
Wireless communications networks generally allow for voice and/or data communication between wireless stations, e.g., wireless telephones (analog, digital cellular and PCS), pagers or data terminals that communicate using RF signals. In recent years, a number of location-based service systems have been implemented or proposed for wireless networks. Such systems generally involve determining location information for a wireless station and processing the location information to provide an output desired for a particular application.
Examples of such existing or proposed applications include emergency or xe2x80x9c911xe2x80x9d applications, location dependent call billing, cell-to-cell handoff and vehicle tracking. In 911 applications, the location of a wireless station is determined when the station is used to place an emergency call. The location is then transmitted to a local emergency dispatcher to assist in responding to the call. In typical location dependent call billing applications, the location of a wireless station is determined, for example, upon placing or receiving a call. This location is then transmitted to a billing system that determines an appropriate billing value based on the location of the wireless station. In handoff applications, wireless location is determined in order to coordinate handoff of call handling between network cells. Vehicle tracking applications are used, for example, to track the location of stolen vehicles. In this regard, the location of a car phone or the like in a stolen vehicle can be transmitted to the appropriate authorities to assist in recovering the vehicle.
From the foregoing, it will be appreciated that location-based service systems involve location finding equipment (LFE) and location-related applications. To some extent, the LFEs and applications have developed independently. In this regard, a number of types of LFEs exist and/or are in development. These include so-called angle of arrival (AOA) time difference of arrival (TDOA), handset global positioning system (GPS) and the use of cell/sector location. The types of equipment employed and the nature of the information received from such equipment vary in a number of ways. First, some of these equipment types, like GPS, are wireless station-based whereas others are xe2x80x9cground-based,xe2x80x9d usually infrastructure-based. Some can determine a wireless station""s location at any time via a polling process, some require that the station be transmitting on the reverse traffic channel (voice channel), and others can only determine location at call origination, termination, and perhaps registration. Moreover, the accuracy with which location can be determined varies significantly from case to case. Accordingly, the outputs from the various LFE""s vary in a number of ways including data format, accuracy and timeliness.
The nature of the information desired for particular applications also varies. For example, for certain applications such as 911, accuracy and timeliness are important. For the applications such as vehicle tracking, continuous or frequent monitoring independent of call placement is a significant consideration. For other applications, such as call billing, location determination at call initiation and call termination or during handoff is generally sufficient.
Heretofore, developers have generally attempted to match available LFEs to particular applications in order to obtain the location information required by the application. This has not always resulted in the best use of available LFE resources for particular applications. Moreover, applications designed to work with a particular LFE can be disabled when information from that LFE is unavailable, e.g., due to limited coverage areas, malfunctions or local conditions interfering with a particular LFE modality. In addition, the conventional query and response mode of operation between applications and the associated LFEs has resulted in the use by applications of LFE dependent data formats, LFE limited data contents, and single LFE input location determinations.
The present invention generally relates to managing the provisioning of location information on a mobile communications unit. A first aspect of the present invention is embodied in a method for providing location information on a mobile communications unit (e.g., wireless telephones, pagers, data terminals) of a mobile communications system (e.g., a wireless communications network). The method generally includes the step of determining at least the general location of a particular mobile communications unit. This information is then used to determine if any of a plurality of position determination equipment sites may be utilized to provide location information on this particular mobile communications unit.
Various refinements exist of the features noted in relation to the subject first aspect of the present invention. Further features may also be incorporated in the subject first aspect of the present invention as well. These refinements and additional features may exist individually or in any combination. The mobile communications system may include a plurality of cells. Each of these cells may encompass a certain geographical area. Typically when the mobile communications unit is being powered or is in an xe2x80x9conxe2x80x9d condition, one or more signals will be exchanged on some basis (e.g., intermittently, periodically) between the mobile communications unit and the cell site equipment (e.g., one or more of a transmitter, receiver, transceiver, or antenna(s)) of the cell in which the mobile communications unit is then physically located. It may be possible for the mobile communications unit to be in this type of communication with multiple cells. Therefore, determining which cell(s) the mobile communications unit is currently communicating with in the above-noted manner may be used to define the general location of the mobile communications unit in accordance with the subject first aspect. That is, the xe2x80x9cgeneral locationxe2x80x9d of the mobile communications unit in accordance with the first aspect may correspond with the area of each of the cells which are in communication with the mobile communications unit in the above-noted manner. Where a cell includes a plurality of cell sectors, this same general technique may be utilized to determine which cell sector(s) is in communication with the mobile communications unit in the above-noted manner.
Another way of conceptualizing the xe2x80x9cgeneral locationxe2x80x9d associated with the subject first aspect is that it encompasses a first area. Knowledge of the geographical description of this first area may be used as a basis for determining which position determination equipment site, if any, includes a coverage area which at least overlaps with this first area.
The determination of which position determination equipment site, if any, would be able to provide location information on a mobile communications unit in accordance with the subject first aspect may entail consulting a database or other appropriate data storage structure having information on these position determination equipment sites. Various types of information may be stored on each position determination equipment site within this database. There will typically be an identifier of sorts which is unique to each particular position determination equipment site, and this information will typically be stored in the noted database. All other information relating to a particular position determination equipment site will then typically be stored in relation to or in association with its corresponding identifier.
Additional information which facilitates the determination of whether a position determination equipment site is available or appropriate for providing location information on a particular mobile communications unit is the geographical description of the coverage area for the particular position determination equipment site. This geographical description of the coverage area may be defined by the physical location of the position determination equipment site (e.g., a latitude and longitude coordinate) and some type of specified function (e.g. an equation for an area of a circle and which includes the relevant radius/diameter). Other ways of defining this geographical description may be implemented as well, such as by providing geographical coordinates which define the perimeter of the coverage area. In any case, knowledge of the general location of the mobile communications unit allows the database to be consulted to determine if the coverage area of any position determination equipment site includes at least part of, or more preferably encompasses, this general location.
Another way in which the first aspect of the present invention may be implemented is to store information on all of the position determination equipment sites that are available for providing location information for a mobile communications unit when within a particular cell or cell sector. Information on position determination equipment sites of this type can be stored for one or more cells and/or cell sectors within the mobile communications network, and more preferably for each of these cells or cell sectors. This may be implemented by one or more appropriately configured databases where each xe2x80x9crecordxe2x80x9d in the database could be on a particular cell or cell sector, and which could then include at least an identification of those position determination equipment sites that are associated with the subject cell or cell sector (e.g., a server address). As noted above, the cell/cell sector of the subject mobile communications unit may be determined such that this database may be consulted to determine which position equipment sites, if any, would be available for providing location information on the mobile communications unit at issue.
Information may also be stored on one or more, and preferably each of, the mobile communications units that are part of the mobile communications network. A database or database structure may be used for this purpose as well. Information that may be stored on a mobile communications unit specific basis and that may be useful in implementing the first aspect is whether or not a particular mobile communications unit has handset-based location finding capabilities, such as GPS. The first aspect of the invention could then be adapted to first determine if the mobile communications unit for which location information is desired has handset-based location finding capabilities, and to consult the cell/position determination equipment site database only if the mobile communications unit of interest does not have handset-based location finding capabilities. This protocol could be reversed whereby the handset-based location finding capabilities of the subject mobile communications unit would only be evaluated if the determination of the general location of the subject mobile communications unit first led to a determination that no position determination equipment site was available for providing the desired location information.
Location information on a mobile communications unit may be requested by one or more location-based systems or applications. Requests for location information may be directed to a location information management system or location manager which executes the functionality of the subject first aspect. Although the location-based applications may be part of or interface with the mobile communications system in at least some manner, the first aspect contemplates that these location-based applications may be in direct communication with this location information management system as well. That is, any way of operatively interconnecting the location information management system and these location-based applications may be utilized in relation to the subject first aspect. In any case, the request for location information on a particular mobile communications unit will be relayed by the location information management system to one or more position determination equipment sites only if the location information management system associated with the first aspect first determines that each such position determination equipment site will be able to actually provide the desired location information. That is, the location information management system associated with the first aspect will not invoke a request for location information to a particular position determination equipment site unless the location information management system first determines that the position determination equipment site will be able to provide the desired location information on the subject mobile communications unit. Consider the case where there are first, second, and third position determination equipment sites, and where the mobile communications unit is physically located within the coverage area of only the first position determination equipment site. In accordance with the foregoing, a request for location information will be invoked only in relation to the first position determination equipment site and not the second or third position determination equipment sites. Related to the foregoing, any location information management system associated with the first aspect of the present invention may be configured so as to invoke a request to a particular mobile communications unit for handset-based location information only if any such location information management system first determines that this particular mobile communications unit does indeed have handset-based location finding capabilities.
The request for location information on a particular mobile communications unit in association with the first aspect may include one or more requirements or prerequisites relating to the desired location information. This may be characterized as a xe2x80x9cquality of service negotiation.xe2x80x9d Each of these requirements may be evaluated in accordance with the subject first aspect of the present invention in relation to determining if any of the position determination equipment sites will be able to provide the location information on the mobile communications unit in accordance with the specified requirements. For instance, the request may include a time limit for receiving the location information on a given mobile communications unit. If a particular position determination equipment site cannot make the location determination within this time limit, a request for location information will not be invoked to this particular position determination equipment site. An acceptable uncertainty associated with the location information may also be included with a request for location information. For instance, a particular request may provide that the location information must be within xc2x110 feet. If a particular position determination equipment site cannot provide location information on a particular mobile communications unit with this degree of accuracy, a request for location information on the particular mobile communications unit will not be invoked to this particular position determination equipment site. Another requirement which may be provided along with a request for location information on a particular mobile communications unit is an acceptable cost or price for receiving this location information, and including in the form of a xe2x80x9cnot to exceedxe2x80x9d amount which is specified. If a particular position determination equipment site cannot provide location information on the particular mobile communications unit within the financial constraints imposed by the request, a request for location information on this mobile communications unit will not be invoked to this particular position determination equipment site. Another factor that may be specified in relation to a request for location information is the xe2x80x9cagexe2x80x9d of the location information. In this case, the first aspect may utilize a database of the like which stores the last known location of at least one of, and more preferably each of, the mobile communications units that are part of the mobile communications network. The first aspect may then be adapted to first consult this information source to determine if the location information that is stored on the mobile communications unit at issue satisfies the corresponding request, and to thereafter proceed with a handset-based position determination evaluation or other position determination equipment site (e.g., network-based) evaluation only if the most recent and stored location information does not satisfy the outstanding request.
Location information on a particular mobile communications unit may be provided to the designated recipient(s) in a number of manners in relation to the subject first aspect of the present invention. Consider the case where multiple position determination equipment sites have first been determined to be available or appropriate for providing location information on a particular mobile communications unit (i.e., multiple position determination equipment sites satisfy all of the requirements associated with the request for location information on a particular mobile communications unit). One option would be to provide the location information to the designated recipient(s) from only one of these position determination equipment sites. This could be random or location information on a particular mobile communications unit could be invoked to the xe2x80x9cbestxe2x80x9d position determination equipment site. Another option would be to provide the location information to the designated recipient(s) from each of these position determination equipment sites. Still another option would be utilize fusion principles or the like where at least two of the position determination equipment sites are each utilized in the derivation of the final location information (e.g., to combine the location information from two or more position determination sites in some maimer to provide a single result).
A second aspect of the present invention is directed toward providing location information on a mobile communications unit of a mobile communications system. A request for location information on a particular mobile communications unit is directed toward a mobile communications unit location information management system. A response to this request is directed toward the requestor (e.g., a particular location-based service system or application). In the case of the subject second aspect, this response is the location information on the desired mobile communications unit. However, this location information must have been derived in a certain manner in accordance with the second aspect. Generally, the location information must be from at least one position determination equipment site which was first determined by the mobile communications unit location information management system to be appropriate for providing the desired location information before the mobile communications unit location information management system actually invoked a request to this particular position determination equipment site for the location information on the particular mobile communications unit.